1. Field of the Invention
The present invention relates to a tool for drilling and/or chiseling and used with a hand-held mechanized tool having a suction device including a housing surrounding the tool, with the tool including a tubular shaft having an axially extending through-channel, and a connection member located opposite a front end of the shaft for connecting the shaft with the housing of the suction device and having a diameter larger than a diameter of the shaft and a cross-bore opening into the through-channel of the shaft.
2. Description of the Prior Art
A tool of the type described above is used for drilling and/or chiseling in stone, concrete, brickwork and similar brittle materials. Tools of this type are known in which the drillings are removed from a drilled or chiseled bore via at least one helical groove provided on the tool shaft. Also known are tools with a suction capability, so-called suction drills. The suction drill has an axial bore connectable with a suction device connectable with a vacuum producing apparatus, in particular, a so-called vacuum cleaner. In comparison with a drill provided with a helical removing groove, the suction drill has a higher drilling capacity and insures a better cleaning of a drilled bore.
A tool formed as a suction drill is disclosed in German Publication DE 198 10 192A1. The known tool is insertable in a hand-held mechanized tool having a suction device including a housing surrounding the tool. The tool has a tubular shaft having an axially extending through-channel. A connection member is located opposite a front end of the shaft and connects the shaft with the housing of the suction device. The connection member has a diameter larger than a diameter of the shaft and has a cross-bore opening into the through-channel of the shaft.
In the tool disclosed in DE 198 10 192A1, the connection member is welded or soldered to the tool shaft. It is also known to form the connection member and the shaft as a one-piece part, as disclosed, e.g., in German Publication De 196 03 528A1. The connection member used in known tool makes the tool not cost-effective, in particular, when the connection member and the shaft are formed as a one-piece member. This is because due to the increased diameter of the tool, an increased amount of machining is needed to form the tool. The maximal diameter of the connection member determines, during the tool manufacture, the diameter of the blank. During the formation of the tool, the regions of the shaft or the shank must be reduced to the desired diameter by machining.
Further, because of the increased mass, which is caused by the connection member, the known tool has a smaller impact energy transmission between the mechanized tool and the, e.g., drill, independent on whether the connection member is formed with the shaft as a one-piece member or as a separate member connectable with the shaft.
Accordingly, an object of the present invention is to provide a tool for drilling and/or chiseling which can be economically produced.
Another object of the invention is to provide a drilling and/or chiseling tool which would permit to optimize the transmission of the impact energy between the mechanized tool and the drilling and/or chiseling tool.
These and other objects of the present invention, which will become apparent hereinafter, are achieved by forming the connection member of a core and at least one adapter surrounding the core.
Forming the connection member of a core and a core surrounding adapter permits to advantageously adapt tools having different shaft diameters to the suction device. Thus, the housing of the suction device can be adapted to a tool having the largest diameter and, in the region of the connection member, the difference in diameters of the tool shafts can be compensated by using adapters having a diameter corresponding to the shaft diameter. This also permits to optimize the tool construction in view of different considerations, e.g., to achieve an optimal energy transmission and/or to reduce manufacturing or operational costs. In addition, with the inventive connection member, a labor-consuming machining is eliminated, and material losses are significantly reduced.
Preferably, the adapter is formed of a material having a lower density than the material the shaft and/or the core are formed of. This permits to achieve an optimal impact energy transmission as the mass in the region of the connection member is reduced. The reduction in mass results from forming the adapter of a material having a lower density than the core material. The undesired mass accumulation in the region of the connection member can be reduced by forming the adapter of a thin-wall material, e.g., sheet steel.
A further reduction of the mass accumulation can be achieved by forming the adapter of a plastic material, e.g., polyamide that has a lower density than steel. The plastic material also favorably influences manufacturing, facilitating the formation and mounting, which reduces manufacturing costs. In addition, the plastic material provides a better elasticity of the adapter and insures good sealing characteristics of the adapter.
When the reduction in costs is paramount, the adapter can fixedly be connected with the core.
With the fixed connection of the adapter with the core, an optimal manufacturing process is connecting the adapter, which is made of a plastic material, with the core by injection molding.
In order to provide for a simple adaptation of tools having different diameters to a particular suction device, the adapter advantageously is releasably connected with the core. In this way, the dimensions of different tools are varied by using different adapters.
The releasable connection of an adapter with a core can be effected by providing on the adapter and the core mating shoulders.